Prospective memory and intellectual disability

• Previous studies have shown prospective memory errors in persons with intellectual disability (adults, Levén et al., 2007, 2008, 2011, 2013, adolescents, Meilan et al., 2009). As prospective memory failures are one of the most common memory errors (Crovitz and Daniel, 1984), this may explain part of the difficulties in handling demands in everyday life for persons with intellectual disability. Prospective memory refers to memory focused on realising intentions in the future. The ongoing task is performed as the intention is stored in long-term memory. Despite research in different clinical groups (brain injuries, Mioni et al., 2013; Aging, Kvavilashvili et al, 2013; schizophrenia, Raskin et al, 2013; ADHD,  Brandimonte et al., 2011, Kliegel, 2013, etc.) this aspect of memory has received little attention in relation to intellectual disability (adults, Levén et al., 2007, 2008, 2011, 2013, adolescents, Meilan et al., 2009).Meilan et al. (2009) got results supporting the multi-process view on prospective memory (McDaniel & Einstein, 1990). The multiprocess view on PM (Einstein & McDaniel, 1990) predicts that the prospective part will be noticed more automatic in specific circumstances, specifically, if the PM cue is either; (a) strongly associated with the planned action, (b) associated with the ongoing task, (c) salient, or (d) has relevant features that come into focus of attention as a result of processing associated with the ongoing task (M. A. McDaniel & Einstein, 2000; M. A. McDaniel, Guynn, Einstein, & Breneiser, 2004).Intellectual disability and prospective memory.Research on prospective memory has increased dramatically in recent years, although persons with intellectual disability have not been thoroughly investigated. Recent studies have studied prospective memory in persons with traumatic brain injury. Persons with intellectual disability may have suffered a brain injury in childhood, but there are also genetic and foremost unknown (about 50%) reasons for intellectual disability.Keeping appointments (Rivermead Behavioural Memory Test) have been found to be a difficult subtest for persons with intellectual disability (Martin et al., 2000; Meilan et al., 2009). The child version of the test has been used in adult persons with Down's syndrome (Aldrich et al., 1991; Wilson 1995). Performance was low also on the borrowed item subtest of the River Mead Behavioural Memory Test. In this task the experimenter borrows an item and the participant is to ask for it later on in the experiment. Prospective memory performance is strongly related to retrospective memory performance in persons with intellectual disability similar as in children. This has been attributed to a general weakness in memory processes such as episodic memory, and/or attention (Levén et al, 2008).Method.Population. The participants in the present study were a subsample drawn from the prospective Betula cohort study testing wave 2. There were 2840 people between 35 and 90 years of age. People with genetic syndromes (e.g. Down syndrome) were excluded in Betula, which gave a mixed or non-specific intellectual disabilities sample. In the Betula database, a group with intellectual disability (IQ < 70, n=58) was defined, using a verbal and a nonverbal IQ test, together with a control group matched on age, sex, level of education and years of education (n=116). Note that these groups were old (mean age = 73 years) compared to most other studies on ID.Tasks: At the beginning of all of the memory tests each day, the test leader asked the subject to remind him/her that they should sign a paper at the end of the day after all the tests were finished. Subjects were not told that this was a memory test. Together with this task on prospective memory, several tasks of episodic memory (recall, recognition), semantic memory (knowledge, fluency) and short-term memory was used.The task was scored as follows:4, recall no cue: Subjects remembered this without any aid3, after cue: Test leader: Was there not something else we should do?2, after reminding: Test leader: Were you not supposed to remind me of something?1, failed completely: Failed to remember despite of cues givenResults.See Table 1 for frequencies for the different prospective memory answers. The controls perform better than persons with intellectual disability on the prospective memory task, F(1,173) = 10.8, p<.001. However, almost all participants with ID managed to perform the task with reminders.Table 1. Frequencies for the prospective memory answers in percent in the two groups.Prospective memory answerIDControls1, failed completely14 %8 %2, recall after reminding53 %25 %3, recall after cue14 %37 %4, recall without cue19 %30 % In the control group, prospective memory correlated significantly with episodic memory (.19), semantic memory (.32) and short-term memory (.22), whereas in the intellectual disability group none of the correlations were significant (episodic memory .16, semantic memory .08, and short-term memory .18). The memory measures were also more intercorrelated in the control group compared to the intellectual disability group. This is contrary to previous results (Levén et al., 2008, 2011, 2013) where the ID group had higher intercorrelations.Discussion.Low prospective memory performance was found in the intellectual disability group as in previous studies. Prospective memory correlated with other memory functions only in the control group. One possibility is that prospective memory loads on executive functions, or vigilance not measured in this study.Persons with intellectual disability have not been able to perform verbal prospective memory tasks at all in previous studies. In this study, on the contrary, persons with intellectual disability performed a verbal prospective memory task. About half of the participants with intellectual disability remembered the prospective memory task if the experimenter asked what they should remind them of. That is, they managed the task with a cue that reduced the load on long-term memory. Previous studies have used a less explicit cue which did not improve performance significantly in the intellectual disability group.Selected ReferencesBrandimonte, M. A., Filippello, P., Coluccia, E., Altgassen, M., & Kliegel, M. (2011). To do or not to do? Prospective memory versus response inhibition in autism spectrum disorder and attention-deficit/hyperactivity disorder. Memory, 19(1), 56-66. doi:10.1080/09658211.2010.535657Einstein, G. O., & McDaniel, M. A. (1990). Normal aging and prospective memory. Journal of Experimental Psychology. Learning, Memory, and Cognition, (4), 717-726.Levén, A., Lyxell, B., Andersson, J., Danielsson, H., & Rönnberg, J. (2011). The relationship between prospective memory, working memory and self-rated memory performance in individuals with intellectual disability. Scandinavian Journal of Disability Research. 1-17.                                           Levén, A., Lyxell, B., Andersson, J., Danielsson, H. & Rönnberg, J. (2008). Prospective memory, working memory, retrospective memory and self-rated memory performance in persons with intellectual disability. Scandinavian Journal of Disability Research. , 10(3), 147-165.Levén, A., Lyxell, B., Andersson, J. & Danielsson, H. (2013). Pictures as cues or as support to verbal cues at encoding and execution of prospective memories in individuals with intellectual disability. Scandinavian Journal of Disability Research.Meilán, J. G., Pérez, E., Arana, J. M., & Carro, J. (2009). Neuropsychological and cognitive factors in event-based prospective memory performance in adolescents and young people with an intellectual disability. British Journal Of Developmental Disabilities, 55(108,Pt1), 61-75. doi:10.1179/096979509799103179Mioni, G., Rendell, P. G., Henry, J. D., Cantagallo, A., & Stablum, F. (2013). An investigation of prospective memory functions in people with traumatic brain injury using Virtual Week. Journal Of Clinical And Experimental Neuropsychology, 35(6), 617-630. doi:10.1080/13803395.2013.804036Wilson, B. A. and Ivani-Chalian, R. (1995), Performance of adults with Down's syndrome on the Children's Version of the Rivermead Behavioural Memory Test: A brief report. British Journal of Clinical Psychology, 34: 85–88. doi: 10.1111/j.2044-8260.1995.tb01440.x

Subject headings

SAMHÄLLSVETENSKAP  -- Psykologi -- Psykologi (hsv//swe)

SOCIAL SCIENCES  -- Psychology -- Psychology (hsv//eng)

Keyword

Prospective memory

intellectual disability

Publication and Content Type

ref (subject category)

kon (subject category)